HM Land Registry records the plot of land for 18, Thomas Street, Mountain Ash as measuring 165 m².

That makes it the 6th largest plot in the postcode, where 24 of the 41 other houses have recorded plot data.

18, Thomas Street, Mountain Ash has an Energy Performance Rating (EPC) of C. This is based on the most recent assessment, dated 19 Feb 2021.

The property is connected to mains gas and has fully double glazed windows. It is heated using a boiler and radiators (mains gas).

The most recent sale of 18, Thomas Street, Mountain Ash completed on 4th June 2004 at £56,500 and was recorded by HM Land Registry as a leasehold house.

Since 1995 this is the property's only sale.

• Sold Jun 2004£56,500

Since 2016 130 properties similar to 18, Thomas Street, Mountain Ash have sold within a radius of 610 metres, per the Land Registry and our network of Estate Agents.

The latest, on the 3rd February 2026, was 3, Gwernifor Street, Mountain Ash, CF45 3NA, a freehold house which sold for £150,000.

Read more about house prices in CF45.

• Sold Feb 2026£150,000 | 3 Bed House3, Gwernifor Street, Mountain Ash, CF45 3NA3, Gwernifor Street, Mountain Ash, CF45 3NA
• Sold Nov 2025£108,000 | 3 Bed House111, Woodfield Terrace, Mountain Ash, CF45 3UT111, Woodfield Terrace, Mountain Ash, CF45 3UT
• Sold Nov 2025£120,000 | 3 Bed House100, Woodfield Terrace, Mountain Ash, CF45 3UT100, Woodfield Terrace, Mountain Ash, CF45 3UT
• Sold Nov 2025£65,000 | 3 Bed House110, Woodfield Terrace, Mountain Ash, CF45 3UT110, Woodfield Terrace, Mountain Ash, CF45 3UT
• Sold Oct 2025£112,000 | 3 Bed House32, Oakland Street, Mountain Ash, CF45 3AL32, Oakland Street, Mountain Ash, CF45 3AL
• Sold Sep 2025£130,000 | 3 Bed House14, Oakland Street, Mountain Ash, CF45 3AL14, Oakland Street, Mountain Ash, CF45 3AL
• Sold Aug 2025£110,000 | 3 Bed House10, Cilhaul Terrace, Mountain Ash, CF45 3ND10, Cilhaul Terrace, Mountain Ash, CF45 3ND
• Sold Jun 2025£135,000 | 3 Bed House3, Glancynon Street, Mountain Ash, CF45 3YU3, Glancynon Street, Mountain Ash, CF45 3YU
• Sold Jun 2025£98,000 | 3 Bed House96, Clarence Street, Mountain Ash, CF45 3BD96, Clarence Street, Mountain Ash, CF45 3BD
• Sold Jun 2025£127,500 | 3 Bed House27, Edward Street, Mountain Ash, CF45 3AJ27, Edward Street, Mountain Ash, CF45 3AJ
• Sold Jul 2024£128,000 | 3 Bed House109, Penrhiwceiber Road, Mountain Ash, CF45 3SF109, Penrhiwceiber Road, Mountain Ash, CF45 3SF
• Sold Jun 2024£47,000 | 3 Bed House40, Thomas Street, Mountain Ash, CF45 3BU40, Thomas Street, Mountain Ash, CF45 3BU
• Sold Apr 2024£117,000 | 3 Bed HouseGlanffrwd Villa, Woodfield Terrace, Mountain Ash, CF45 3UTGlanffrwd Villa, Woodfield Terrace, Mountain Ash, CF45 3UT
• Sold Nov 2023£148,000 | 3 Bed House22, Edward Street, Mountain Ash, CF45 3AJ22, Edward Street, Mountain Ash, CF45 3AJ
• Sold May 2023£115,000 | 3 Bed House40, Oakland Street, Mountain Ash, CF45 3AL40, Oakland Street, Mountain Ash, CF45 3AL
• Sold Jan 2022£85,000 | 3 Bed House39, Thomas Street, Mountain Ash, CF45 3BU39, Thomas Street, Mountain Ash, CF45 3BU
• Sold Jan 2022£135,000 | 3 Bed House29, Oakland Street, Mountain Ash, CF45 3AL29, Oakland Street, Mountain Ash, CF45 3AL
• Sold Feb 2021£57,500 | 3 Bed House14, Thomas Street, Mountain Ash, CF45 3BU14, Thomas Street, Mountain Ash, CF45 3BU
• Sold Oct 2019£58,900 | 3 Bed House37, Oakland Street, Mountain Ash, CF45 3AL37, Oakland Street, Mountain Ash, CF45 3AL
• Sold Jun 2016£34,000 | 3 Bed House32, Thomas Street, Mountain Ash, CF45 3BU32, Thomas Street, Mountain Ash, CF45 3BU

Of the 73 addresses on Thomas Street, Mountain Ash, CF45, 18, Thomas Street, Mountain Ash comes out as the 13th largest and the 11th most expensive in our analysis of the public data.

It is also £15k less expensive than the average property across the CF45 district.

• Mountain Ash

  |

  800 m away
• Penrhiwceiber

  |

  1.0 km away
• Fernhill

  |

  2.1 km away

The flood risk here is rated Very Low, based on Environment Agency data.